Field of the Invention
The present invention relates to an image forming apparatus that is capable of preventing a sheet from falling and going astray at the time of jam handling processing.
Description of the Related Art
Conventionally, an image forming apparatus, such as a copy machine, is provided with an inversion conveying section for inverting the front and reverse sides of a sheet to perform face-down discharge or double-sided printing. The inversion conveying section has a conveyance path for conveying a sheet in a vertical direction, and is configured to convey a sheet in a state nipped between pairs of rollers disposed on sheet guide walls on opposite sides of the conveyance path, and invert the front and reverse sides of the sheet by switching back the sheet. Further, to make it easy to remove a sheet remaining in the conveyance path when a jam occurs, the inversion conveying section is configured to have, for example, a structure capable of being opened and closed by forming one of the guide walls inside an opening/closing door of the image forming apparatus.
In the inversion conveying section having the structure capable of being opened and closed, when one of the guide walls is opened to perform jam handling processing, nipping of a sheet between the pairs of rollers is released so that the sheet remaining in the conveyance path falls. As a result, the sheet goes astray outside the image forming apparatus, and even when a sheet falls within the apparatus, the sheet may slide into a place where it is difficult for a user to take out the sheet. For this reason, the inversion conveying section capable of being opened and closed is a factor that lowers the jam handling processing performance of the image forming apparatus.
Incidentally, the reason why a sheet falls when one of the guide walls of the inversion conveying section is opened is that one of the rollers of each roller pair within the conveyance path is disposed on one of the guide walls which is capable of being opened and closed, and cannot keep nipping the sheet when the one of the guide walls is opened. To solve this problem, there has been proposed a sheet conveying device or an image forming apparatus that is additionally provided with a retaining member for retaining a sheet, and causes the retaining member to move to a position where it retains the sheet, in a manner interlocked with opening of the guide wall, to thereby prevent the sheet from falling (see Japanese Patent Laid-Open Publication No. 2000-247525).
However, the above-mentioned conventional technique has a problem that it is necessary to add a new mechanism to the inversion conveying section, and hence a dedicated space for the new mechanism is required, thus leading to an increase in the manufacturing cost.